The performance of any communications system in terms of throughput (data rate) can be improved according to Shannon's Law (described below) in either of two ways:                1. Improved Bandwidth and Bandwidth Efficiency                    by increasing the channel bandwidth            by improving the bandwidth efficiency through efficient signal modulation techniques and signal processing methods for improving bandwidth efficiency                        2. Improved Signal-to-Noise Ratio (SNR)                    by increasing signal power            by decreasing noise powerMost technical advances in wireless communications systems have focused on the first of the above—bandwidth and bandwidth efficiency. Though not as commonly addressed, possible approaches to improving on SNR may include implementing advanced antenna technology. By increasing the gain of both directional and omnidirectional antennas, it is possible to expand the capabilities of broadband wireless by increasing signal levels which increases throughput performance in accordance with Shannon's Law.                        
It is also possible to improve SNR to a much higher level by attaching a high gain, low noise preamplifier to the antenna for much greater signal gain. This combination is known by the designation “active antenna” since it includes an active electronic component augmenting the gain of the passive antenna. In common practice, this preamplifier would be electronic in nature and require electric power for its operation. Such electronics and power requirements significantly increase the complexity and cost of the active antenna.
Magnetic amplifiers in power and control applications were used extensively in World War II, particularly by the Germans in a variety of military roles. Magnetic amplifiers experienced a brief resurgence in the U.S. in the 1950s as a possible replacement for vacuum tubes, but the advent of power transistors and other solid state power devices led to a decline of interest.
Improvements in both directional and omnidirectional antenna technology as well as magnetic preamplifiers are possible by employing singly or together the concepts of circuit resonance and ferrite magnetic amplification. Circuit resonance achieves higher gain by narrowing the bandwidth of an antenna using a series or parallel resonant circuit in which inductive reactance is cancelled by an equal and opposite capacitive reactance. The ratio of the inductive reactance to circuit resistance determines the Q gain value of the circuit. The feasibility of this approach depends on the basic antenna or amplifier circuit having sufficient inductance to produce high Q values. Loop antennas and their various solenoid, helix and loop Yagi derivatives have this characteristic. Magnetic preamplifiers also may be structured with the required high inductance.
Resonant and ferrite antenna amplification both depend on the original basic antenna configuration. In general, helix antennas are preferable because of their higher gain to turn ratio. Solenoids require a large number of turns to achieve any gain alone and are, therefore, completely dependent on the resonant or ferrite circuit for their gain enhancement. Loop Yagi antennas are more complex in their design and require the determination of design parameters by experimentation.
Conventional wireless communications systems, such as those employing WiFi (IEEE Standard 802.11), WiMAX (IEEE Standard 802.16) and other advanced wireless communications technologies, rely on conventional antennas. The operational and functional characteristics of such antennas determine the range and throughput of these broadband wireless communications systems. In some applications, as in low population density rural areas, broadband wireless communications systems may not be economically feasible with conventional antennas. Without higher gain antennas and/or supporting preamplifiers, the number of access points (antenna base stations) required to cover a geographic area may be excessive, considering the number of potential users in the area. Installation of higher gain antennas at both user premises and network access points may significantly extend the range of each access point, thereby greatly reducing the number of access points needed to cover a specified geographic area.
WiFi and Narrowband Personal Communications Services (PCS) networks conventionally deploy omnidirectional antennas in mobile devices (for example, cellular telephones) configured to work in their communications networks. Conventional omnidirectional antennas available for use in these mobile devices are typically low gain monopole antennas. While arrays of directional antennas may be used at base stations, these mobile devices with low gain antennas may drive a need for a greater density of fixed antennas to permit a desired level of operability and geographic coverage of these conventional networks.
The result of the use of these low gain antennas in mobile devices may be the weak link in these wireless communication networks, according to Shannon's Law. In addition, increasing efficiency of base station or fixed antennas may also aid in the expansion of conventional wireless telecommunications networks.
Improvements to conventional antennas for wireless communications networks are desirable.